Deployment of a compact, transportable, fully automated Josephson voltage standard

A compact, transportable, Josephson voltage standard, first reported at CPEM96, has now been field tested and has had ten months of use as a primary standard by the National Aeronautics and Space Administration (NASA) laboratories. We discuss here its uncertainty assessment, the results of inter-comparisons with conventional Josephson standards, operator training, and the experience of users. A second similar standard with an improved microwave system has been fabricated at the National Institute of Standards and Technology (NIST) and delivered to Sandia National Laboratories (SNL) for use by Department of Energy (DOE) standards laboratories